The quantitative analysis of arsenic in food can be carried out using HVG with flame atomic absorption spectrophotometry (AAS)(1) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) methods. Inorganic arsenic exists in trivalent and pentavalent forms, and in seafood, arsenic is mainly found in organic form(2). In order to decompose this organic arsenic and any other co-existing organic substances, nitric acid is added to the sample followed by thermal decomposition. As a result of this process, arsenic is changed to pentavalent form. However, because arsenic reacts to form hydrides in trivalent form, the sample must be pre-reduced by adding potassium iodide in order to ensure all the arsenic is in trivalent form. On the other hand, reduction will not take place properly if there is any nitric acid left and so after thermal decomposition, the sample is heated until almost dry to evaporate all the nitric acid. This data sheet demonstrates the analysis of arsenic in canned fish using both AAS-HVG and (ICP-AES)-HVG methods.